Electrical & Conversion Tools

Free electrical engineering calculators and unit converters. From Ohm's law to currency exchange — all in one place.

electrical_services Electrical Engineering

Calculate how much an appliance costs to run per day, month and year.

Convert between joules, calories, kilowatt-hours, BTU and other energy units.

Calculate voltage, current, resistance and power using Ohm's law.

Decode 4, 5 or 6 band resistor colour codes to find resistance and tolerance.

Check your cable meets the BS 7671 maximum 5% voltage drop requirement.

Find the correct cable size for UK installations based on current and length.

Convert between GBP, USD, EUR and other major currencies.

Convert between metres, feet, inches, kilometres, miles and more.

Convert between Celsius, Fahrenheit and Kelvin instantly.

Convert between kilograms, pounds, stones, ounces and grams.